Heating device for refrigerator temperature controls



Sept. 7, 1954 c. D. HARRIS 2,688,234

HEATING DEVICE FOR REFRIGERATOR TEMPERATURE CONTROLS FiledApril 12, 1952Patented Sept. 7, 1954 HEATING DEVICE FOR REFRIGERATOR TEMPERATURECONTROLS Charles D. Harris, Evansville, Ind., assignor to InternationalHarvester Company, a corporation of New Jersey Application April 12,1952, Serial No.- 281,985

Claims.

This invention relates generally to refrigeration apparatus and moreparticularly to a device for heating the temperature control unit of arefrigerator cabinet.

The majority of the refrigerator cabinets being manufactured today areprovided with a temperature control unit which automatically regulatesthe operation of the refrigeration system so that the interior of thecabinet will be maintained within a desired temperature range. Thetemperature control unit is generally located between the inner linerand outer shell of the cabinet in such a position that it can be easilyreached for manual adjustment. In many instances, the outer casing ofthe temperature control unit will be cooled by the transfer of heat tothe cold surfaces of the inner liner which results in the formation ofcondensate or frost on the outer surfaces of the unit. This conditionprevents proper operation of the temperature control unit whereby thefood storage compartment will not be maintained at the requiredtemperature. The present invention provides a means for overcoming thisproblem.

One object of the present invention is to provide means for preventingcondensateor frost from collecting on a temperature control unit.

Another object of the present invention is to provide means forsupplying heat to a temperature control unit from the refrigerationsystem of a refrigerated cabinet.

A further object of the invention is to position amember of arefrigeration system in close proximity to a temperature control unitwhereby said unit will be heated by the high pressure refrigerant withinsaid member.

A still further object of the invention is to provide a refrigeratedcabinet with a refrigeration system having a condenser and an evaporatorconnected by a conduitwhich is disposed with a portion thereof in heatexchange relation to a temperature control unit.

The foregoing and numerous other objects will appear from the followingdetailed description of preferred embodiments of the invention whenconsidered in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a refrigerated cabinet in which thepresent invention is incorporated.

Fig. 2 is a diagrammatic view of thgrefrigeration system for therefrigerated cabinet shown in Fig. 1.

Fig. 3 is a front elevational view of the refrigerated cabinet showing amodified form of the invention.

Fig. 4 is an enlarged sectional view taken along line 4-4 of Fig. 1..

Fig. 5 is an enlarged sectional view taken along line 55 of Fig. 3.

Referring to the drawings for a detailed description of the invention, arefrigerated cabinet is designated by reference numeral I 0. Althoughthe cabinet I0 is illustrated in the form of a vertical type householdrefrigerator, it is to be understood that this is for illustrativepurposes only and that the invention as described hereinafter is not tobe limited to such a cabinet. An inner liner II is spaced within anouter shell I2 with insulating material It therebetween. The inner linerI I forms a food storage compartment I4 and a door I5 is hinged to thecabinet Ii which closes and seals the food storage compartment when in aclosed position. The compartment I4 may be provided with shelves I6 anddrawers I! to facilitate the storage of food articles. An evaporator I8is secured in the upper corner of the compartment I4 over which airwithin the compartment I Al will circulate and be cooled.

The outer edges of the inner liner II are provided with inturned flangesI9 which project toward the outer shell I2. The edges of the outer shellI2 are provided with flanges 20 which eX- tend inwardly toward the innerliner II. The space between the edges of the inner liner I i and outershell I2 is covered by an upper breaker strip 2 I, a lower breaker strip22 and side breaker strips 23 and 24. The breaker strips bridge acrossthe flanges I9 and 20 and are secured thereto by clips or other suitablemeans. By constructing the breaker strips from a heat insulatingmaterial, the transfer of heat between the inner line I I and outershell I2 will be reduced substantially. The upper breaker strip 2| isprovided with a circular opening 25 therethrough to which a temperaturecontrol device 26 is secured.

Details of the temperature control device 26 are not shown since thedevice could be any one of the many types available on the market today.The temperature control 26 is positioned in a compartment 21 providedwithin the insulating material I 3' and is attached to a U-shapedbracket 28 having the ends 29 and 30 thereof secured to the breakerstrip H by any suitable means such as the snap spring 3I. A control knob32 fits within the circular opening 25 and is fixedly secured to a shaft33 which projects from the temperature control 26. A small diameteredtube 3 1 connects the temperature control 26 to a control bulb 35 whichis disposed within the food storage compartment I4. Any change intemperature of the compartment I4 will be registered on "the 3temperature control 28 by the bulb 35 and tube 34.

The refrigeration system for the cabinet ll] is diagrammaticallyrepresented in Fig. 2 of the drawings. It comprises a motor-compressorunit 36, a condenser 31 and the evaporator I8. After being compressed bythe motor-compressor unit 36, the refrigerant is conveyed to thecondenser 31 by a conduit 39. As the refrigerant flows through thecondenser 31, it is cooled and condensed, then forwarded through tube 40to a capillary tube 41. The refrigerant is metered into the evaporator[8 by the capillary tube 41 and then returned to the motor-compressorunit 36 by conduit 42. The motor-compressor unit 36 is energized by asuitable electric circuit (not shown). The temperature control device 26is connected into the electric circuit by leads 43 and 44 in such amanner that the compressor unit 36 will be started and stopped wheneverthe bulb 35 is subjected to predetermined temperatures.

A preferred embodiment of the invention is illustrated in Figs. 2 and 4of the drawings. The tube 40 extends from the condenser 31 adjacent theinturned flange 20 of the outer shell l2 into the compartment 21 withinthe insulating material l3. In the illustration the tube 40 is providedwith a looped portion 45 which encircles the temperature control unit26. The food storage compartment [4 will be maintained at a lowtemperature by the evaporator l8 and heat leakage will cause the casingof the temperature control unit 21 to be cooled to the dew point of theair. If this condition prevailed, moisture or frost would collect on theouter surfaces of the temperature control unit 26 and prevent the unitfrom functioning properly. The purpose of the tube 40 is to prevent theformation of condensate or frost on the temperature control unit 26. Therefrigerant which flows through the tube 40 is maintained at a hightemperature and pressure by the refrigeration system. Heat from therefrigerant will be emitted by the looped portion 45 of the tube 40.Since the temperature control unit 26 is surrounded by the loopedportion 45, it will be heated thereby to a temperature above the dewpoint of the air within compartment 21 so that the problem ofcondensation thereon will be eliminated. In the drawings the tube 40 isillustrated as having one turn encircling the temperature control unit26 but it is to be understood that a greater number of turns may beprovided if required.

A second embodiment of the invention is shown in Figs. 3 and of thedrawings. In this structure the tube 40 is provided with an offsetportion 46 to which the temperature control unit 26 is secured by meansof a, clip 41. As best seen in Fig. 5, the clip 41 comprises a curvedportion 48 and end portions 49 and 50. The clip is positioned with thecurved portion 48 over the tube 40 and the end portions 49 and 50contacting said unit 26 and being secured thereto by appropriate means.The tube 40 and temperature control unit 26 are held in heat exchangerelation whereby the temperature control 26 will be heated by the hotrefrigerant being circulated through the tube 40. This will heat theouter surfaces of the temperature control unit 26 above the dew pointtemperature of the surrounding air so that there will be no moisturecondensed thereon.

The invention illustrated and described provides an effective means forpreventing the accumulation of condensate or frost on the temperaturecontrol device 26 of the refrigerator cabinet Ill. The tube 40 serves toheat the temperature control 26 as well as to convey refrigerant fromthe condenser 31 to the evaporator 3 so that a complicated structure isnot required for proper operation of the refrigeration system.

While the forms of embodiments of the present invention as hereindisclosed constitute preferred forms, it is to be understood that otherforms might be adapted without departing from the spirit of theinvention or from the scope of the appended claims.

What is claimed is:

1. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system comprising a compressor, condenser, evaporator andmetering device, said evaporator being located within a storage chamberenclosed by said inner liner, a temperature control unit located inclose proximity to said storage chamber for controlling the operation ofsaid compressor, a tube connecting said condenser to said meteringdevice, said tube having a portion located in heat exchange relation tosaid temperature control unit whereby the unit will be maintained at atemperature above the dew point of the surrounding air.

2. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system comprising a compressor, condenser, evaporator andmetering device, said evaporator being located within a storage chamberenclosed by said inner liner, a compartment provided within saidinsulating material, a temperature control unit positioned in saidcompartment for controlling the operation of said compressor, a tubeconnecting said condenser to said metering device, said tube having aportion located in heat exchange relation to said temperature controlunit whereby the unit will be maintained at a temperature above the dewpoint of the surrounding air.

3. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, a breakerstrip bridging between said outer shell and said inner liner, arefrigeration system comprising a compressor, condenser, evaporator andmetering device, said evaporator being located within a storage chamberenclosed by said inner liner, 2. compartment provided within saidinsulating material proximate said breaker strip, a temperature controlunit positioned in said compartment for controlling the operation ofsaid compressor, a tube connecting said condenser to said meteringdevice, said tube having a portion extending through said compartment inheat exchange relation to said temperature control unit so that the unitwill be heated by the tube and maintained at a temperature above the dewpoint of the surrounding air.

4. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system for cooling a storage chamber enclosed by saidinner liner, a temperature control unit located between said inner linerand said outer shell for controlling the operation of said refrigerationsystem, a tube connected into said refrigeration system so thatcompressed refrigerant flows therethrough, said tube having a curvedportion which extends around a portion of said temperature control unitin close proximity thereto whereby the unit will be maintained at atemperature above the dew point of the surrounding air.

5. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system comprising a compressor, condenser and evaporatorwhich is located within a storage chamber enclosed by said inner liner,a compartment provided within said insulating material, a temperaturecontrol unit positioned in said compartment for controlling theoperation of said compressor, a tube connecting said condenser to saidevaporator, said tube having a looped portion which encircles saidtemperature control unit whereby the unit will be heated and maintainedat a temperature above the dew point of the air in said compartment.

6. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system comprising a compressor, condenser and evaporatorwhich is located within a storage chamber enclosed by said inner liner,a compartment provided within said insulating material, a temperaturecontrol unit positioned in said compartrnent for controlling theoperation of said compressor, a tube connecting said condenser to saidevaporator, and clip means for securing said temperature control unit inthermal contact with said tube whereby the unit will be heated andmaintained above the dew point temperature of the air in saidcompartment.

7. In a refrigerated cabinet, an outer shell and an inner liner spacedtherein with insulating material therebetween, a refrigeration systemfor cooling a food compartment enclosed by said inner liner, saidrefrigeration system including a continuous length of tubing having arefrigerant flowing therethrough, said refrigerant flowing therethroughhaving a temperature relative to the temperature of said length oftubing to cause said length of tubing to be heated by said refrigerant,a thermostatically operated device secured to said cabinet forcontrolling the operation of said refrigeration system, a portion ofsaid length of tubing positioned in a contiguous relationship to saidthermostatically operated device, whereby said thermostatically operateddevice is in a heat exchange relationship with and is heated by saidlength of tubing, whereby said thermostatically operated device will bemaintained at a higher temperature than said food compartment.

8. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system for cooling a storage compartment enclosed by saidinner liner, a thermostatically operated temperature control unitlocated between a wall of said inner liner and a wall of said outershell for controlling the operation of said refrigeration system, saidrefrigeration system including a continuous length of tubing having arefrigerant flowing therethrough, said refrigerant flowing through saidlength of tubing having a temperature relative to the temperature ofsaid length of tubing to cause said length of tubing to be heated bysaid refrigerant, a portion of said length of tubing positioned in acontiguous relationship to said thermostatically operated temperaturecontrol unit, whereby said thermostatically operated temperature controlunit is in a heat exchange relationship with and is heated by saidlength of tubing, whereby said thermostatically operated temperaturecontrol unit will be maintained at a higher temperature than saidstorage compartment.

9. In a refrigerated cabinet having an inner liner spaced Within anouter shell with insulating material disposed therebetween, arefrigeration system for cooling a storage chamber enclosed by saidinner liner, a compartment provided in said insulating material, athermostatically operated temperature control unit positioned in saidcompartment for controlling the operation of said refrigeration system,said refrigeration system including a continuous length of tubing havinga refrigerant flowing therethrough, said continuous length of tubingpositioned in a portion of said refrigeration system wherein a warmrefrigerant is caused to flow through said length of tubing, wherebysaid length of tubing is heated by said refrigerant flowingtherethrough, a portion of said length of tubing positioned in acontiguous relationship to said thermostatically operated temperaturecontrol unit, whereby said thermostatically operated temperature controlunit is in a heat exchange relationship with and is heated by saidlength of tubing to a degree wherein the thermostatically operatedtemperature control unit will be maintained at a temperature above thedew point of the air within said compartment.

10. In a refrigerated cabinet having an inner liner spaced within anouter shell with insulating material disposed therebetween, arefrigeration system for cooling a storage chamber enclosed by saidinner liner, a thermostatically operated temperature control unitpositioned between said inner liner and said outer shell for controllingthe operation of said refrigeration system, said refrigeration systemincluding a continuous length of tubing having a refrigerant flowingtherethrough, said refrigerant flowing through said continuous length oftubing having a temperature relative to the temperature of said lengthof tubing such as to cause said length of tubing to be heated by saidrefrigerant, a portion of said length of tubing positioned in acontinguous relationship to said thermostatically operated temperaturecontrol unit, and means for securing said thermostatically operatedtemperature control unit to said contiguous portion of said tube whereysaid thermostatically operated temperature control unit will be heatedby said contiguous portion of said tube, and whereby saidthermostatically operated temperature control unit is maintained at atemperature above the dew point of the surrounding air.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Re 20,2 15 Hoffman June 12, 1937 1,852,707 Hoffman Apr. 5,1932 2,060,774 Zurcher Nov. 10, 1936 2,135,091 Newill Nov. 1, 19382,163,698 Money June 27, 1939 2,207,125 Kuebler July 7, 1940 2,391,030Morrison Dec. 18, 1945 2,471,448 Platon May 31, 1949 2,477,055 GiffordJuly 26, 1949 2,598,335 Alsing May 27, 1952 2,598,408 McCloy May 27,1952

